Oct 27 Regrowing Severed Limbs Was Once NBD

If humans could regrow limbs like salamanders, would that make severed-limb Halloween costumes more or less exciting?

For all of you lovers of gore who plan on parading around with severed limbs this week, consider this: If evolution hadn't gotten all fancy with how it builds our arms and legs, we might be able to regenerate limbs as easily as salamanders who can regrow limbs throughout their lifetimes. I can't decide if this would make the severed-limb costume more or less exciting, but in the Nature paper that just came out discussing this revelation, I am proud to say that I illustrated the press release with... guess what! That's right: severed limbs. Convenient timing don't ya think? For the record, when I did the illustration I had no idea it would come out the week of Halloween. Muah-ah-ahhhh!

For those interested in the nuts and bolts of how researchers Nadia Fröbisch et. al figured out that certain fossil species could regenerate their limbs and tails, the original Nature paper and the Brown University press release explain the findings in detail. Spoiler alert: No, they did not take tiny hacksaws to fossils and wait 50 million years to see if anything would grow back. Lucky for them, a fair number of fossils show partially regenerated limbs and evidence of limb regeneration gone wrong: oddly misshapen limbs that mirror common mistakes we observe today, particularly when salamanders regenerate their limbs multiple times. The paper has pretty compelling photos of the best of these fossils, so check it out.